Definition & Source of Primary & Secondary Corrosion Inhibitors

[fcesar]

I'm looking for the definition of "Primary Corrosion inhibitor" and the source.
Common sense tells me that primary corrosion inhibitor is the product you use to treat your primary corrosion problem. Secondary corrosion inhibitor, as the word say, is the product used as “safety” to prevent other types of corrosion other then your primary. "Let you sleep at night" type
The chemist (a contractor) treating our industrial water system is trying to tell me that primary corrosion inhibitor is a "list of products" such as PO4, poly phosphate, silicates, etc...
From what I understand, those products are commonly used as primary corrosion inhibitors, but that does not make them ALWAYS the primary, it depends on the use you are making, not the product itself.
I'm not a chemist and I'm being tagged as "I don't know what I'm talking about".
Can someone help me find the definition of primary and secondary corrosion inhibitors and most important, the source or reference that I can bring to a meeting with this chemist.
Please correct me if I'm wrong.
Thank you

 

[Astronuc]

This paper mentions primary and supplemental (or secondary) agents.

http://www.nace.org/nacestore/assets/ConferencePapers/2000/00659.pdf

The primary inhibitors directly affect the galvanic or reduction/oxidation reactions - e.g. reducing/oxidizing agents or film formers.

The supplemental or secondary inhibitors affect intermediate or indirect steps. e.g. pH/buffer, conductivity of the solution, . . .

Here is a nice tutorial on corrosion -
http://www.gc3.com/techdb/manual/corrfs.htm